Refrigeration technicians need to use extreme care when working with torches during the brazing and soldering process. The flames of a torch can easily reach 3,000°F. At this temperature, serious damage can be the result of misuse and carelessness. Not only can this lead to personal injury, but it could also result in severe property damage.
There are several general safety rules that should be followed while handling torches. Some safety precautions apply before the brazing/soldering process begins, others apply during the process, and some apply after the process is complete.
Safety initially begins during the transporting of the acetylene and, if used, oxygen cylinders. Always transport cylinders in a well-ventilated vehicle. Never transport cylinders in an enclosed compartment within a vehicle. Cylinder valves should always be closed during transport. Make sure the valve covers are in place and regulators are removed prior to transporting. Be sure to always properly secure cylinders in an upright, vertical position, separated from the driver’s compartment. Cylinder brackets are a great option for securing tanks in transport.
Before using a torch on a system, a technician should be cautious of the surrounding area. They should make sure the area does not contain any combustible materials such as oily components, rags, or insulation. They should also make sure they have a fire extinguisher readily available. Always make sure the tubing to be brazed or soldered does not contain any refrigerant or oil. Halogen refrigerant, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs) can decompose if exposed to high temperatures such as those from a flame. When they decompose, they will form very hazardous compounds. If this does occur, a strong pungent odor will be produced, warning a technician of the hazard.
Always make sure the cylinders are secured to a solid base, such as a bench or freestanding kit designed for the torch cylinders. You definitely do not want these cylinders tipping over while in use. When opening the valve of an acetylene or oxygen cylinder, stand off to the side. The valve on an acetylene cylinder should be open no more than one full turn. If using an oxygen tank, its valve should be fully open when in use. Both the oxygen and acetylene hoses should also be purged prior to use. Acetylene is unstable above 15 psig and should never be set above this pressure. While lighting a torch, never use an open flame from a butane lighter. A torch should always be lit with a striker.
While using the torch, always be conscious of the surrounding area. If necessary, use heat shields to protect the surrounding material and heat paste to protect the component. When done, if using an oxygen-acetylene torch, shut down the oxygen first and then the acetylene and always check the surrounding area for any signs of potential hot spots that could lead to a fire later on.
When handled properly, these torches can be used safely and provide a reliable heat source for a technician. When mishandled, they can become a severe safety hazard.
Publication date: 5/5/2014